I postponed this post by a day in an attempt to get my Word Bearers Helbrute finished paint wise but unfortunately this has not happened so I'm going to release the post anyway.
The Helbrute is essentially a Chaos Dreadnought, which isn't a great starting point in this edition. Traditionally, there have been 3 ways to kit out a Dreadnought. For Close combat, for ranged support and for dropping in and shooting a tank. We can rule out the latter because drop pods are not available in the Chaos Codex. Also think that we can discount the former.
With the coming of 6th edition close combat Dreadnought suffered a serious downgrade. Firstly, you can't tie up things as effectively any more, due to the fact that now if you are unable to harm a unit you can choose to fail your leadership check at the end of the combat, leaving it.
Additionally, anything that can hurt you is probably going to be doing so with Grenades, and I'll likely have enough bodies to bring you down. Even if they don't , they may have combat tactics to simply walk out of the combat anyway and shoot you to death.
Even if the Helbrute does somehow end up tying a unit up, it doesn't do enough damage to make up his points. Besides, he's slow and unlikely to get into combat with anything that wants to avoid him.
So, the only option left is to build him in a shooty kind of way. Right? Well there are a few problems with this. Ok, he's 100pts stock and for his durability that's not appalling. It's not fantastic value but it is not that bad.
So how much damage can he put out? Well the first point of call would be to swap out his power fist, as a close combat it is kind of redundant. You can swap this out for a missile launcher for an extra 10% of its points cost, and that's it. It doesn't even come with Flakk. So the only really variety in shooting weapons comes when you swap out your stock shooting weapon, which makes sense, but isn't very helpful.
You can get another power fist, which you shouldn't touch. A twin-linked heavy bolter for 5% extra, a reaper autocannon for the same, a plasma cannon for double, or a twin-linked Lascannon for an extra 25%.
You're going to want something that complements the Missile Launcher. Something long range, that can deal with light-medium armoured vehicles and high toughness models but also able to do a little against infantry.
Well the only option that matches the range of the Missile Launcher is the twin Lascannon, which is overcosted and not great against infantry. And then everything else is 12" shorter, which isn't bad.
I probably wouldn't go for the heavy bolter. It isn't high enough strength to damage vehicles and it doesn't pump out enough shots with that and it's medium AP to be fantastic against most infantry. Anything with a low armour saves has too many bodies to care, and anything with a good armour value doesn't care because of it.
So that leaves the Autocannon and the Plasma Cannon. The Autocannon is Twin-linked, and is probably a tad better for vehicle killing, whilst the Plasma cannon benefits from the lower AP and thus is better for heavy infantry death. It's all a matter of preference, because in my mind none of this really matters.
The Helbrute also 'benefits' from the Crazed special rule. This comes into effect every time it suffers a glancing or penetrating hit.
The first possibility is quite helpful. Although it is immobilised, all of its weapons fire twice that shooting phase. Although the target unit must be the one that caused the damage, which is why duality is important. The problem being that you don't get to choose the target, meaning that your opponent can often bait it's fire.
The second one is ok now that rage isn't a downside, so it recovers from shaken and stunned results.
The third one is equally unhelpful. It is the same as the previous roll but also means that your Helbrute must run toward the enemy, robbing you of your shooting phase and forcing you to move backwards to avoid running out of the cover that you will have initially placed your Helbrute in to make it more durable.
So, if your Helbrute is damaged, there is a 66% chance that you won't be able to fire at your preferred target this turn.
To sum up, you can't drop out of the sky and take out a vehicle, close combat dreadnoughts are dead, and you'll struggle to make a decent shooting platform out of it. Cool model, fun rules, but not particularly competitive. That said, as I have the model, I might as well try to make it work.